Continuous cleaning apparatus

ABSTRACT

A continuous treating apparatus such as used for the abrasive cleaning of castings includes a treating chamber which communicates with an infeed chamber and an exit chamber, at least one of which is tubular. A spiral article conveyor is mounted on the inner surface of the tubular chamber and a center tube or bridging element is disposed at the entrance of the tubular chamber and connected to the first flight of the spiral conveyor.

United States Patent Inventor Willard .1. Harper llagerstown, Md.

Appl. No. 815,379

Filed Apr. 11, 1969 Patented June 22, 1971 Assignee The Carborundum Company Niagara Falls, N.Y.

CONTINUOUS CLEANING APPARATUS 13 Claims, 12 DrawingFigs.

us. or 51/13, 51/9, 51/164 B24c 3/30 51/9, 13, 164

[56] References Cited UNITED STATES PATENTS 1,642,632 9/ l 927 Titgen 51/164 2,441,578 5/1948 Keefer 51/13 2,574,867 11/1951 Gladfe1ter.. 51/13 2,724,929 1 1 1955 Moore 51/13 Primary Examiner-Lester M. Swingle Attorney-Connolly and Hutz ABSTRACT: A continuous treating apparatus such as used for the abrasive cleaning of castings includes a treating chamber which communicates with an infeed chamber and an exit chamber, at least one of which is tubular. A spiral article con veyor is mounted on the inner surface of the tubular chamber and a center tube or bridging element is disposed at the entrance of the tubular chamber and connected to the first flight of the spiral conveyor.

PATENTEH Jurizzlsn 3585758 sum 3 [1F 3 CONTINUOUSCLEANING APPARATUS BACKGROUND OF INVENTION Continuous treating devices have been used for blast cleaning castings. Examples of these devices are described in U.S. Pat. Nos. 2,574,867; 2,724,929; and 2,441,578. Such machines have been quite successful for cleaning high-volume small to medium castings, since the machines can handle large tonnages of the same parts or miscellaneous parts and handle them automatically. The most successful machines such as referred to above include both an infeed drum or chamber and an exit drum or chamber. These drums incorporate helicoid flights or spirals to accomplish two different functions. One function is to feed the work to and from the barrel or cleaning chamber of the machine. The second function is to prevent abrasive particles from rebounding out of the machine.

Although these spirals effectively solve the abrasive retention problem they also create other serious problems. One particular problem is the breakage of processed parts. For example as the parts enter the infeed drum the first flight of the spiral must shear or cut through the bed of castings. With some casting shapes such as automobile intake manifolds, breakage is quite high. The same condition also exists at the entrance to the exit drum spiral. Another problem with the infeed and exit drum spirals is that the infeed drum spiral pushes the work into and through the cleaning chamber while the exit drum spiral at times tends to restrict the movement of the parts thus creating high thrust loads on the drum thrust rollers. With certain shaped parts this problem is particularly acute.

. SUMMARY OF INVENTION An object of this invention is to provide a treating apparatus of the above type which eliminates the above-indicated problems.

In accordance with this invention a bridging element is disposed at the entrance of the spiral containing drum and is connected to the first flight of the spiral. In this manner the articles are deposited between flights of the spiral and thus the first flight is prevented from cutting through a bed of such articles.

The bridging element is preferably a tubular section coaxially arranged with respect to its drum. A transmission section on the bridging element may be connected to the second flight of the spiral. The second flight may include an opening disposed above the transmission section so that articles may slide off the transmission section and be deposited between the second and third flights of the spiral. The transmission section may slope downwardly away from the second flight to direct the articles between the first and second flights of the spiral.

When the tubular bridging element is arranged in the exit chamber the bridging element may advantageously be shaped either in a converging or diverging or even straight form in accordance with the needs for a particular cleaning operation. For example, with certain parts which are discharged at a relatively fast rate from the treating chamber, it is most advantageous to form the bridging element in a diverging manner thus minimin'ng any tendency for back up or jamming of the parts. With other parts, however, it is desirable to retain the parts in the treating chamber as long as possible whereupon the bridging section can be made in a converging shape or can be straight and incorporate a damming element.

In a further aspect of this invention the tubular bridging ele ment can be disposed around but spaced from a floating ring connected to the treating chamber whereby the treating chamber and exit drum can have independent drives. In this mannerjamming of the parts can be minimized for example by rotating the exit drum at a faster speed than the treating chamber. Additionally, the floating ring arrangement may be utilized at the infeed chamber and separate drives used for each of the infeed chamber, the treating chamber and the exit chamber.

THE DRAWINGS FIG. I is a cross-sectional view in elevation of a prior art arrangement;

FIG. 2 is an end view in elevation of a treating apparatus in accordance with this invention;

FIG. 3 is a cross-sectional view taken through FIG. 2 along the line 3-3;

FIG. 4 is a cross-sectional view taken through FIG. 3 along the line 4-4;

FIG. 5 is a cross-sectional side view in elevation of the apparatus shown in FIGS. 2-4;

FIG. 6 is a cross-sectional view taken through FIG. 3 along the line 6-6;

FIG. 7 is a perspective view partly broken away of a portion of the apparatus shown in FIGS. 2-6;

FIG. 8 is an end view in elevation ofa modified form of this invention;

FIG. 9 is a side view partly in section of the apparatus shown in FIG. 8;

FIG. 10 and II are side views partly in section of other forms of this invention; and

FIG. 12 is an enlarged view in elevation of a portion of the apparatus shown in FIG. 10.

DETAILED DESCRIPTION FIG. I shows a prior art continuous treating apparatus I which includes a spiral conveyor in for example the infeed drum 2. The castings 3 are generally deposited in the infeed drum between the first flight 4 and the infeed entrance to create a bed of castings. As the drum and its conveyor rotate the leading edge 5 of the first flight 4 cuts through the bed of castings frequently shearing many of the castings and lifting others which eventually fall and are sometimes broken.

The present invention eliminates the shearing action of the leading edge of the spiral conveyor by in effect providing a center tube at the entrance of the conveyor to assure that the parts or articles being treated will be deposited between flights of the spiral so that the leading edge does not cut through a bed of such parts.

FIG. 3 shows a treating apparatus 10 formed in accordance with this invention. Many of its features, such as the drives, are of the conventional type as exemplified by U.S. Pat. No. 2,574,867. As indicated in FIG. 3 the parts are deposited in the infeed chamber of drum I2 and then flow into the treating section I4 which is for example in the form of a flexible troughlike conveyor having spaced slats so that the parts can be tumbled therein while abrasive particles are projected from blast wheels 16 to clean the parts. The abrasive particles may then fall between the slats and into screw conveyor 18 for separation and further use. The drive 20 for the endless flexible conveyor is illustrated in FIG. 4 and also in FIG. 1. A detailed discussion of this drive is not necessary since its details thereof do not form a part of this invention.

From the treating chamber 14 the parts are fed into exit drum 22 and are discharged at for example 23.

Within each tubular chamber 12 and 22 a spiral conveyor 24, 26 is provided. A center tube or bridging element 28, 30 is arranged at the entrance to each chamber, as described in detail hereinafter, and extends to at least the first flight of the spiral. In the preferred form of this invention both the infeed section 12 and exit section 22 are tubular and are provided with the spiral conveyor and bridging element. It would, however, be possible to utilize for example the spiral conveyor and bridging element in only one of the chambers without departing from the spirit of this invention. As used in this description the term flight" means a 360 portion of the spiral. For example, the first flight 32 (FIG. 7) begins at the leading edge 34 and terminates 360 therefrom with the next portion of the spiral being the second flight 36 which is integral with the first flight 32.

As illustrated in FIGS. 3, 5 and 7 the first flight 32 has an axial opening, with the center tube or bridging element 28 extending to this opening from the entrance of infeed section 12.

The edge of center tube 28 at the entrance of drum 12 is circular while the remote edge follows the contour of the spiral conveyor. With the inclusion of center tube 28 the bed of parts to be cleaned fonns between the conveyor flights so that the leading edge 34 does not have any shearing action on the It has been found, however, that as the parts are deposited in the rotation center tube 28 the parts tend to move in the forward direction. Accordingly, the second flight 36 is provided with an opening or cutaway section 38 and the center tube includes an integral transmission section which extends to the second flight. Thus the sliding parts may fall through the opening 38 and may be deposited between the second and third flights of the spiral conveyor. The transmission section 4-0 is of triangular shape and may be flattened or sloped away from second flight 36 to prevent too many parts from sliding between the second and third flights and thus tend to urge the pans to fall into the pocket formed between the first and second flights.

The bridging tube 30 at the entrance to the exit chamber 22 may of course be of the same general configuration as bridging tube 28.

FIGS. 8-41 illustrate other shapes for the bridging tubes. Although these FIGS. illustrate the particular bridging tubes in an exit chamber such shapes may also be incorporated in the infeed chamber. As shown in FIG. 9 the bridging element or center tube 30a is straight (i.e. neither divergent nor convergent). If it is desired to increase the bed depth in treating chamber 14 a darn 42 may be provided on the inner surface of center tube 30a. In the form shown in FIGS. 8 and 9 dam 42 is simply a circular flange attached to the inner surface of the center tube. The dam, however, may take other shapes such as sloping toward the treating chamber.

FIG. 10 illustrates still another shape in which the center tube 30b is divergent to prevent the parts from jamming. FIG. 11 shows still another shape wherein the center tube 30c is convergent to have the same effect as the dam (FIG. 9).

In accordance with still another aspect of this invention the drive for the rotating infeed chamber 12 and for the treating chamber 14 may be the same drive as used for the exit chamber 22 so that all three chambers will be rotated at the same speed. In this regard the endless slatted conveyor which constitutes the treating chamber 14 requires a rigid tube over a portion of its circumference to impart an arcuate shape to the flexible conveyor. Conveniently infeed chamber 12 acts as the rigid tube at one end of the slatted conveyor while the center tube or bridging element 30 gives shape to the slatted conveyor at the other end thereof. FIG. 11 for example shows how center tube 30c rests directly against the slatted conveyor 44.

In certain operations, however, it is desirable to rotate the exit drum at a faster speed than the treating chamber to cause the parts to be discharged from the exit chamber faster than the parts are fed into it and thus prevent damming. FIGS. 10 and 12 illustrate a mode of accomplishing this function by providing what may be considered a floating ring 46 at the entrance of exit chamber 22. Ring 46 rests against slatted conveyor 44 to impart an arcuate shape to the slatted conveyor. Accordingly, ring 46 will rotate at the same speed as infeed chamber 12. The center tube 30b is disposed around but spaced from floating ring 46 so that the exit chamber 22 may be rotated by its own independent drive means such as schematically indicated by the numeral 48 in FIG. 10. A guide surface 50 (FIG.12) may be provided to prevent lateral drifting of the floating ring 46. Of course the floating ring concept may be used with straight or converging center tubes as well as with the diverging center tube.

In accordance with another aspect of this invention the floating ring arrangement may be incorporated between the infeed chamber 12 and the treating drum with a separate drive provided for the infeed chamber. Thus each of the infeed, treating and exit chambers may have its own drive or the infeed chamber may have one drive and both the treating and ritshamba hat 9. M r

The treating apparatus of this invention thus effectively eliminates any possibility of the leading edge of the spiral causing breakage to the castings. Additionally, by the selection of particular shapes for the center tubes or bridging elements and by the utilization of independent drives, it is possible to afford control on the flow of parts through the apparatus.

What I claim is:

1. A continuous treating apparatus comprising a treating chamber, treating means disposed adjacent said treating chamber for subjecting the articles in said treating chamber to a treating operation, an infeed chamber communicating with said treating chamber, an exit chamber communication with said treating chamber, at least one of said infeed chamber and said exit chamber being tubular, a spiral article conveyor mounted on the inner surface of said tubular chamber, means for rotating said tubular chamber and its spiral conveyor, at least the first flight of said spiral conveyor having an axial opening, and a bridging element disposed at the entrance of said tubular chamber and extending to said axial opening of said first flight and connected thereto to prevent the leading edge of said first flight from cutting through the articles being inserted into said tubular chamber.

2. An apparatus as set forth in claim 1 wherein said bridging element is a tubular section coaxially arranged with said tubular chamber.

3. An apparatus as set forth in claim 2 wherein said tubular section is connected to said first flight around a full 360, said tubular section including a transmission section connected to the second flight of said spiral conveyor, and said transmission section tapering outwardly toward said second flight.

4. An apparatus as set forth in claim 3 wherein said second flight includes a cutaway portion terminating at said transmission section whereby articles may slide off said transmission section between said second flight and the third flight of said spiral conveyor.

5. An apparatus as set forth in claim 4 wherein said cutaway portion slopes downwardly away from said second flight.

6. An apparatus as set forth in claim 5 wherein each of said infeed chamber and said exit chamber is tubular and includes said spiral conveyor and said tubular bridging element with said transmission section.

7. An apparatus as set forth in claim 1 wherein said exit chamber is tubular and has said spiral article conveyor mounted on its inner surface, said bridging element being a center tube extending from the beginning of said exit chamber to the first flight of said spiral conveyor.

8. An apparatus as set forth in claim 7 wherein said center tube diverges toward said first flight.

9. An apparatus as set forth in claim 7 wherein said center tube converges toward said first flight.

10. An apparatus as set forth in claim 7 wherein a damming element is disposed at the beginning of said exit chamber.

II. An apparatus as set forth in claim 7 wherein said treating chamber includes an endless flexible conveyor drive, said center tube being disposed against said flexible conveyor drive to impart an arcuate shape to a portion of said flexible conveyor drive, said means for rotating said tubular chamber also being rotation means for said treating chamber.

12. An apparatus as set forth in claim 7 wherein said treating chamber includes an endless flexible conveyor drive, a floating ring being disposed against said flexible conveyor drive to impart an arcuate shape to a portion of said flexible conveyor drive, rotation means for rotating said treating chamber, said center tube being disposed around and spaced from said floating ring, and said means for rotating said tubular chamber being independent of said treating chamber rotation means whereby said treating chamber and said exit chamber may rotate at different speeds.

13. An apparatus as set forth in claim 12 wherein a further floating ring is disposed against said flexible drive conveyor adjacent said infeed chamber, said infeed chamber being tubular and having a spiral article conveyor mounted on its inner surface, said tubular infeed chamber being disposed around and spaced from said further floating ring, infeed rotatioii means for rotating said infeed chamber, and said infeed rotation means being independent of said treating chamber rotation means and of said means for rotating said exit chamber. 

1. A continuous treating apparatus comprising a treating chamber, treating means disposed adjacent said treating chamber for subjecting the articles in said treating chamber to a treating operation, an infeed chamber communicating with said treating chamber, an exit chamber communication with said treating chamber, at least one of said infeed chamber and said exit chamber being tubular, a spiral article conveyor mounted on the inner surface of said tubular chamber, means for rotating said tubular chamber and its spiral conveyor, at least the first flight of said spiral conveyor having an axial opening, and a bridging element disposed at the entrance of said tubular chamber and extending to said axial opening of said first flight and connected thereto to prevent the leading edge of said first flight from cutting through the articles being inserted into said tubular chamber.
 2. An apparatus as set forth in claim 1 wherein said bridging element is a tubular section coaxially arranged with said tubular chamber.
 3. An apparatus as set forth in claim 2 wherein said tubular section is connected to said first flight around a full 360* , said tubular section including a transmission section connected to the second flight of said spiral conveyor, and said transmission section tapering outwardly toward said second flight.
 4. An apparatus as set forth in claim 3 wherein said second flight includes a cutaway portion terminating at said transmission section whereby articles may slide off said transmission section between said second flight and the third flight of said spiral conveyor.
 5. An apparatus as set forth in claim 4 wherein said cutaway portion slopes downwardly away from said second flight.
 6. An apparatus as set forth in claim 5 wherein each of said infeed chamber and said exit chamber is tubular and includes said spiral conveyor and said tubular bridging element with said transmission section.
 7. An apparatus as set forth in claim 1 wherein said exit chamber is tubular and has said spiral article conveyor mounted on its inner surface, said bridging element being a center tube extending from the beginning of said exit chamber to the first flight of said spiral conveyor.
 8. An apparatus as set forth in claim 7 wherein said center tube diverges toward said first flight.
 9. An apparatus as set forth in claim 7 wherein said center tube converges toward said first flight.
 10. An apparatus as set forth in claim 7 wherein a damming element is disposed at the beginning of said exit chamber.
 11. An apparAtus as set forth in claim 7 wherein said treating chamber includes an endless flexible conveyor drive, said center tube being disposed against said flexible conveyor drive to impart an arcuate shape to a portion of said flexible conveyor drive, said means for rotating said tubular chamber also being rotation means for said treating chamber.
 12. An apparatus as set forth in claim 7 wherein said treating chamber includes an endless flexible conveyor drive, a floating ring being disposed against said flexible conveyor drive to impart an arcuate shape to a portion of said flexible conveyor drive, rotation means for rotating said treating chamber, said center tube being disposed around and spaced from said floating ring, and said means for rotating said tubular chamber being independent of said treating chamber rotation means whereby said treating chamber and said exit chamber may rotate at different speeds.
 13. An apparatus as set forth in claim 12 wherein a further floating ring is disposed against said flexible drive conveyor adjacent said infeed chamber, said infeed chamber being tubular and having a spiral article conveyor mounted on its inner surface, said tubular infeed chamber being disposed around and spaced from said further floating ring, infeed rotation means for rotating said infeed chamber, and said infeed rotation means being independent of said treating chamber rotation means and of said means for rotating said exit chamber. 